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Kernel: Cleanup NVMe Queue command submission 

There is techically a race condition on thread sleep and checking
done mask. This patch allows read to success even if this race
condition is hit, although the full timeout has to be waited.

This can be fixed in future with some sort of wait queues that
can properly handle this race condition.
This commit is contained in:
Bananymous 2024-03-19 12:55:13 +02:00
parent 7f5c850744
commit 62f6128ba1
1 changed files with 12 additions and 16 deletions
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28
kernel/kernel/Storage/NVMe/Queue.cpp
View File

@ -67,24 +67,20 @@ namespace Kernel
}
const uint64_t start_time = SystemTimer::get().ms_since_boot();
while (SystemTimer::get().ms_since_boot() < start_time + s_nvme_command_poll_timeout_ms)
{
if (m_done_mask & cid_mask)
{
uint16_t status = m_status_codes[cid];
m_used_mask &= ~cid_mask;
return status;
}
}
while (!(m_done_mask & cid_mask) && SystemTimer::get().ms_since_boot() < start_time + s_nvme_command_poll_timeout_ms)
continue;
while (SystemTimer::get().ms_since_boot() < start_time + s_nvme_command_timeout_ms)
// FIXME: Here is a possible race condition if done mask is set before
// scheduler has put the current thread blocking.
// EINTR should also be handled here.
while (!(m_done_mask & cid_mask) && SystemTimer::get().ms_since_boot() < start_time + s_nvme_command_timeout_ms)
Scheduler::get().block_current_thread(&m_semaphore, start_time + s_nvme_command_timeout_ms);
if (m_done_mask & cid_mask)
{
if (m_done_mask & cid_mask)
{
uint16_t status = m_status_codes[cid];
m_used_mask &= ~cid_mask;
return status;
}
uint16_t status = m_status_codes[cid];
m_used_mask &= ~cid_mask;
return status;
}
m_used_mask &= ~cid_mask;